Electronic component housing for use in hostile environments

ABSTRACT

A housing for electronic components that includes a tubular, extruded aluminum, mid-section, a flat or plate-like front panel and a die-cast double-domed rear wall. Arranged in one of the domes of the rear wall is a printed circuit board with first female plugs. Fitting through the second dome, from the outside, are second female plugs, to which outwardly-leading cables are attached. Circuit boards with integrated electronic circuits slide into the housing and are secured laterally by guide grooves integral with the middle section of the housing. The boards, at their frontal edges, make contact through their male plugs with the appropriate ones of the female plugs. The boards are further secured by fitting into notches in a reinforcement rib between the two domes. A strip having three contact points is secured, if desired, to each circuit board for the purpose of reducing mechanical vibration. Each circuit board can be replaced individually. For this purpose, withdrawal arms are provided.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a housing for electronic componentssuitable for use in hostile environments, and, more particularly, tosuch housing having connectors for electronic components and also havingelectronic components mounted therein.

2. Background of the Prior Art

Housings and switch boxes of various embodiments suitable foraccommodating electronic circuits are generally known. Known inparticular from patent EP 0 078 405 is a built-in plastic housing,whereby a cover and a floor portion are secured by special means to oneor more annular middle sections. This method permits the size of thehousing to be increased or decreased in stages.

Also generally known are service elements such as connecting elements(e.g. sockets or male plugs) which, being installed on the front and/orrear walls of such housings, enable the attachment of mating elementsfor the purpose of electrically connecting the housing to itsenvironment. Such sockets and/or male plugs are connected in the housingthrough suitable wiring arrangements to normally parallel-arrangedadjacent circuit boards comprising the electronic components of theoverall electronic system.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a stable andcost-effective housing for small electronic circuitry arrangements thatis capable of operating in hostile environments while permitting anadequate transfer to the outside of heat generated by the electroniccomponents. The proposed housing should be connected to its environmentthrough a plurality of male plugs, sockets or female plugs.

In keeping with this object, there is provided in accordance with oneaspect of the present invention a housing suitable for use in hostileenvironments and serving to mechanically secure and electrically connecta plurality of plug-in type circuit boards that bear integratedelectronic circuits and that are arranged parallel to one another. Thehousing comprises a tubular, rectangular cross-sectioned, rigid middlesection, a front panel and rear wall. The front panel and rear wall aredetachably secured to the middle section covering respectively oppositeopen ends thereof. The rear wall comprises a rigid, die-cast sectionhaving two domes separated one from the other by a reinforcing ribhaving therein a plurality of spaced-apart guide notches. The guidenotches serve to laterally or frontally secure circuit boards which canbe located within the housing. One of the domes on the rear wall isadapted to accommodate a printed circuit board that bears a plurality offirst male/female plugs facing the interior of the housing. A pluralityof one part of second male/female plugs are detachably secured to thehousing and projecting through the second dome of the rear wall into thehousing. A cable of conductors extend from the second male/female plugs.Guide grooves opposite one another in the interior of the middle sectionare arranged slidably receiving opposite edges of respective ones of aplurality of plug-in type circuit boards that bear integrated electroniccircuits and are arranged in spaced-apart, parallel relationship. Thecircuit boards have another part of male/female plugs for directelectrical contact with the corresponding first and/or secondmale/female plugs upon insertion into the housing.

For a better understanding of the present invention, reference is madeto the following description and accompanying drawings while the scopeof the invention will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by way of example in the accompanyingdrawings wherein:

FIG. 1 is an end view of a middle section of the proposed housing;

FIG. 2 is a front end view of an assembled housing of the presentinvention;

FIG. 3 is a top plan view of the assembled housing of the presentinvention;

FIG. 4 is a sectional view through the rear wall only of the housingtaken essentially along the line A--A of FIG. 3; and

FIG. 5 is a cross-sectional view of the assembled housing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 there is illustrated a frontal end view of a middle section 11of the housing 10 of the present invention. The midsection 11 is anopen-ended, tube-like structure having opposite lateral walls 12, 13, afloor wall 14 and an upper side or top wall 15. The housing midsection11 is an extruded, preferably metal, unitary section that is generallyrectangular in cross-section. Arranged on the inside of each wall 12,13, 14 and 15 of the housing are guide grooves 19', on the outersurfaces screw fastening grooves 21 are provided and at the corner,grooves 23 are provided. The grooves are defined effectively by closelyadjacent ribs and thus may be considered as raised from the wall. Eachof such grooves runs parallel to and along the length of the middlesection 11 from one end to the other.

FIG. 2 is a frontal view of a fully-assembled electronics housing 10featuring a rectangular, flat front panel 25 which, although comprisingno service or display elements, is securely anchored to the front end ofmiddle section 11 by means of a plurality, e.g. ten, self-tapping screws28 that screw into the grooves 21 on middle section 11. Sealing betweenthe end of the midsection and the frontal panel 25 can be improved bythe installation of a sealing component, e.g. an annular sealing stripor gasket, between the components and, if desired, located in a groovein one of the components.

FIG. 3 is a plan view of the housing 10. Flat front panel 25 is fastenedas described above to the front open end of the middle section 11 byscrews 28 that thread into grooves 21. A rear wall 31 is likewisefastened, closing the open rear opposite end of the midsection 11, bymeans of self-tapping screws 28 which are threaded into grooves 21. Asealing strip or gasket can, at the other end, be inserted between thewall and middle section 11. In place of self tapping screws, long bolts,if desired, can be used extending from one cover to the other so as tofasten both end covers 25 and 31 at the same time and clamp themidsection 11 therebetween.

Rear wall 31 features, on one half of its surface, a closed dome 32.Detachably secured (by screws, for example) to the other half of cover31 is a support 33 or dome, which in turn, has a plurality of plugs 35,(only the uppermost one of which is visible) detachably secured (againby screws, for example) thereto. A cable 36 of conductors extends to theoutside from each plug 35.

FIG. 4 is a section through rear wall 31 along line A-A of FIG. 3.Arranged on the inside of the dome 32 are eyes 40, to which can beattached (by screws by example) a (not illustrated) circuit board.Provided on the inner face is reinforcement ribs 41 which in turn has aplurality of guide notches 42. The rear wall 31 as seen from FIG. 4, haseye holes 43 for receiving the fastening screws 28.

FIG. 5 is a cut-away plan view of the interior of housing 10, whereinare arranged a plurality of horizontally disposed, verticallyspaced-apart and parallel to one another, circuit boards 51 (e.g. five)containing electronic integrated circuits 52. Circuit boards (printedcircuit boards) 51 have their opposite edges 54, 55 fitting into guidegrooves, which can be either the grooves 19 as previously describedforming part of middle piece 11, or grooves arranged in separate guidepanels 64, 65. The frontal edges 57 of circuit boards 51 are situated inthe guide notches 42 of reinforcement rib 41. Arranged on frontalborders 57 should ideally be two male plugs 61, 62 of which one, 61,connects directly by its pins to female plugs 35 which are, as alreadydescribed, detachably secured (as by screws) onto housing 10. The othermale plug, 62, connects to further female plugs 67, which are arrangedon a wiring board 68. The wiring board 68 is securely fastened (with theaid of eyes 40, of FIG. 4) inside dome 32, and set orthogonally tocircuit boards 51, and acts essentially to interconnect circuit boards51.

When front panel 25 is removed, circuit boards 51 can be removedindividually from housing 10. For this purpose, circuit boards 51feature two swing or pivoted arms 69, 70 which, lying against thehousing walls, serve to exert outwardpulling leverage on circuit boards51. Each female plug 35 can, for testing or trial purposes, beindividually removed or exchanged.

This arrangement fulfills the requirements and objects set forth above.The arrangement is quite compact and avoids unnecessary wiring. Middlesection 11 is designed preferably as a section of an extrusion-moldedaluminum tube. Rear wall 31 and support 33 are, preferably, of die-castaluminum. This assembly forms, together with the flat front panel 25, astable, cost- effective, fully metal housing that permits the effectivetransfer of heat from the electronic components to the outside whilebeing suitable for employment in hostile environments such as, forexample, inside railway locomotives.

The dimension of middle section 11 should ideally be such that circuitboards 51 of the double European standard size can be used in thehorizontal direction, as described above, while circuit boards of thestandard European format can be used in the vertical direction

The corner grooves 23 can accommodate any desired number of screws forthe purpose of screwing housing 10 to not-illustrated support elements.To this end, sliding or pushing nuts can be slid into such grooves 23.The finished assembly can be attached by the front panel to, e.g., a 19"frame, provided that front panel 25 is larger than the cross section ofmiddle section 11 and possesses screw holes suitable for accommodatingthe 19" standard frame.

In another version, a strip 73, which is provided with notches, isscrewed or otherwise secured onto front panel 25. The notches of strip73, together with the guide notches 42 of reinforcement 41 of rear wall31, act to guide circuit board 51 along its front 57 and outer edges. AnE-shaped strip 75 screwed onto circuit boards 51 to extend from strip 73to reinforcement 41, acts to sharply reduce vibrations in boards 51,which can be caused, for example, by mechanical shocks to housing 10.

While the foregoing description and drawings represent the preferredembodiments of the present invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the true spirit and scope of the presentinvention.

I claim:
 1. A housing suitable for use in hostile environments andserving to mechanically secure and electrically connect a plurality ofplug-in type circuit boards that bear integrated electronic circuits andthat are arranged parallel to one another, said housing comprising: atubular, rectangular crosssectioned, rigid middle section, a front paneland a rear wall, said front panel and rear wall being detachably securedto said middle section covering respectively opposite open ends thereof;said rear wall including a rigid die-cast section having first andsecond domes, said first dome having a first plurality of male/femaleplugs and said second dome having a second plurality of male/femaleplugs; said first and second domes being separated one from the other bya reinforcing rib having therein a plurality of spaced-apart guidenotches, said guide notches serving to laterally or frontally secure aplurality of plug-in type circuit boards which can be located withinsaid housing; said first dome on said rear wall being adapted toaccommodate a printed circuit board having male/female plugs that matewith said first plurality of male/female plugs within the first dome;said second plurality of male/female plugs being detachably secured tothe housing and projecting through said second dome of said rear wallinto the housing, a cable of conductors extending from said secondplurality of male/female plugs; guide grooves opposite one another on aninterior surface of the middle section for slidably receiving oppositeedges of respective ones of a plurality of plug-in type circuit boardsthat bear integrated electronic circuits and are arranged inspaced-apart, parallel relationship, said circuit boards having anotherpart of male/female plugs for direct electrical contact with thecorresponding first and/or second male/female plugs upon insertion intothe housing.
 2. A housing in accordance with claim 1, wherein saidmiddle portion, rear wall and front panel are metal.
 3. A housingaccording to claim 2 wherein said metal is aluminum, said middle portionbeing extruded.
 4. A housing in accordance with claim 1, wherein saidsecond plurality of male/female plugs are secured to said second dome insuch a way that said second plurality of male/female plugs can, whensaid housing is closed, be removed individually from outside thehousing.
 5. A housing in accordance with claim 3, wherein said secondplurality of male/female plug is fastened by means of screws.
 6. Ahousing in accordance with claim 1, wherein said front panel includes astrip on its inside surface having grooves in which each circuit boardis secured additionally on its fourth edge.
 7. A housing in accordancewith claims 1 or 6, wherein each circuit board bears an E-shaped stripserving to reduce mechanical vibrations, and extending, on afully-assembled circuit board, essentially between said strip and saidreinforcing rib.
 8. A housing in accordance with claim 1, whereinarranged on the outside of middle section and as an integral part ofsaid middle section, are corner grooves into which nuts can be slid forthe purpose of fastening said housing to support elements by means ofscrews.
 9. A housing including plug-in type circuit boards mountedtherein suitable for use in hostile environments, said housing servingto mechanically secure and removably receive a plurality of plug-in typecircuit boards that bear integrated electronic circuits and that arearranged parallel to one another, said housing comprising: an openended, tubular-shaped, rigid middle section, a front panel detachablysecured to said middle section and covering one open end thereof and arear wall detachably secured to the middle section and covering theopposite open end thereof; said middle section being anextrusion-formed, generally rectangular in cross-section, rigid memberhaving grooves in the walls thereof, means anchorable in selected onesof said grooves detachably to secure said front panel and rear wall tosaid middle section; a plurality of plug-in type circuit boards slidablyfitted into grooves in the interior of said housing; said rear wallincluding a metallic die-cast section having two domes separated onefrom the other by a reinforcement rib having guide notches serving toreceive a frontal edge of the respective circuit boards; a printedcircuit board being arranged on the inside of one of said domes of saidrear wall and having a first plurality of female plugs; a secondplurality of female plugs projecting through said second dome of saidrear wall, a cable extending from said second female plugs; each saidcircuit board being mechanically secured along three of its edges byguide grooves located opposite one another in said housing and a guidenotch in said rear wall, said circuit boards having plugs makingelectrical contact with the corresponding first and/or second femaleplugs through one or more flat and/or second male plugs arranged uponsaid circuit boards.
 10. An electronic component comprising: a housingthat includes a unitary tubular middle section open at opposite endsthereof; a flat plate-like front panel detachably secured to said middlesection and covering one of the open ends thereof; a double-domed rearwall detachably secured to said middle section and covering the other ofthe open ends thereof; a printed circuit board with first female plugsarranged in one of said domes of said rear wall; second female plugs, towhich outwardly-leading cables are attached fitting through said seconddome from the outside thereof and a plurality of circuit boards slidablymounted in opposite side walls interiorly of said middle section, saidcircuit boards further having their respective frontal edges projectinginto notches in a reinforcement rib on said rear wall, said circuitboards having male plugs at their frontal edge mating with selected onesof said first and second female plugs.
 11. An electronic component asdefined in claim 10 further including a strip having three contactpoints, secured to each said circuit board for the purpose of reducingmechanical vibration.
 12. An electronic component as defined in claim 10wherein said housing middle portion, rear wall and front panel comprisealuminum.
 13. An electronic component as defined in claim 10 including astrip on said front panel having grooves, in which each circuit board issecured additionally on its fourth edge.
 14. An electronic component asdefined in claim 10 including grooves on the inner and outer surfaces ofsaid middle section extending from one to the other of said open ends.